Syncrude Canada has been charged by the Alberta Energy Regulator (AER) for the deaths of 31 blue herons, who died after landing near an abandoned sump at the company’s Mildred Lake site in August 2015.

Syncrude has been charged with one count under the Environmental Protection and Enhancement Act for “for failing to store a hazardous substance in a manner that ensures that it does not come into direct contact with, or contaminate, animals,” the AER announced in a Thursday press release. If convicted, Syncrude could face a fine of up to $500,000.

“Syncrude knows the public expects us to provide energy in a responsible way,” Syncrude spokesperson Will Gibson said in a Thursday interview.

“Our goal is to prevent the deaths of birds and other wildfire as a result of our operation,” he continued.

“We are very saddened and deeply regret the deaths of these blue herons.”

An injured heron was found by Syncrude field workers on Aug. 5, 2015, with further investigation finding another 30 herons near the sump. The incident was reported to the AER on Aug. 7. Of the 31 herons, one bird was still alive but had to be euthanized.

The area the herons were discovered in contained runoff water and bitumen, the AER said at the time. Gibson could not confirm which substances were found in the area.

“What happened has strengthened our resolve to make sure deterrent systems are everywhere they are needed on our sites,” Gibson said.

After a 2008 incident where 1,600 birds died after landing in a tailings pond, resulting in a fine of $3 million, Syncrude implemented a waterfowl protection plan to deter a repeat event. In the last two years that plan had been updated to include inactive pumphouse sites like the one the herons died in during August 2015, Gibson said.

Gibson said he could not provide details of these updates with an impending court case.

“We must review the charges in detail before we decide how we will proceed,” he said.

In a statement, Greenpeace Canada said that while it welcomes the charges, the government needs to increase penalties for such offenses and take action on waste water and tailings ponds.

“A fine that can be paid off by a few hours’ profit doesn’t send much of a signal to the company or to industry, and as long as these toxic ponds and lakes are around, these preventable deaths will continue to happen,” the statement read.

The first court appearance for the case is set for Sept. 27, 2017 in Fort McMurray.